Building construction



Mar. 20, 1923. I 1,448,888.

C. 0. WALPER.

BUILDlNG CONSTRUCTION.

FILED AUG-20.1921.

CURRY ORA. WALPER,OIE' DETROIT, MICHIGAN, ASSIGNOR 0F ONE-THIRD TO FR A.BMSLEN AND ONE-THIRD T0 BERNARD E. CLARK, BCTH- 0F DETROIT, MICHIG.

BUILDING CONSTRUCTION.

Application filed August 20, 1921. Serial NO. 4i93,921.

To all whom it may concern:

Be it known that I, CURRY ORA WALPER,

a citizen of the United States of America,

residing at Detroit, in the county of Wayne and State of Michigan, haveinvented ceris a specification, reference beinghad there-' in to theaccompanying drawings.

This invention has for its primary object to provide a system offinishing a wall or ceiling made of plaster boards so that crackswill.not appear in the finished wall at the points where the variouspanels meet.

In the drawings Figure 1 is a section. of a preferred embodiment of theinvention in place upon a supporting framework.

Fig. 2 is an elevation of the construction shown in Fig. 1, parts beingbroken away;

Fig. 3 is a section showing the manner of protecting the nail heads usedin securing the boards to their supports and also the means forreinforcing the joint to prevent cracking of the finishing coat.

Many forms of wall boards have been proposed and some are now upon themarket, in which paper pulp forms an important or principal portion ofthe material. Such boards are usually not sufficiently resistant toflames and hence are not approved by the buildingcodes for use instructures above a certain size or within certain areas. Warping andshrinking caused by atmospheric changes render such plaster substitutesgenerally unsatisfactory. Other boards are in use in which gypsumplaster is an important constituent, the surfaces of these boardsusually being covered with pasteboard. In ship-ping and handling, suchboards are frequently broken especially at the edges and the pasteboardis not of sufficient strength to prevle-nt the boards from pulling loosefrom the nails used to secure the material to its support. Reinforcingcorner pieces and cords or wires along the edges have been proposed forsuch boards, but the lack of uniformity in areas to be coverednecessitates cutting the boards, thus rendering corner pieces uselessand edge cords of no value. Moreover, plaster boards with paper surfacesare not suited to receive a plaster finishing coat and are not permittedby the codes in many structure's.

When such plaster boards are used, expansion and shrinkage cause thefinishing coat to crack along the line of the joint, spoiling theappearance of the wall.

In the preferred construction of wall board a substantially fireproofplastic composition is used for the body of the board, and substantiallyinextensible reinforcing and nailing strips are embedded within thematerial to extend substantially the; full Width of the board adjacentto the rear surface. Into whatever width the material may be cut, thenailing strips are at the edges to receive the securing nails, and areso located as to resist pressure applied between the supports, thusfurnishing the necessary tensile strength at the point where it is mostneeded. In addition, a secondary reinforcing fabric is embedded withinthe material adjacent to the front surface to support the plastic bodyduring shipment and while it is being handled, but this secondaryreinforcement lies beneath the surface of the plastic body so that theouter face is of the proper material to receive an adhering finishingcoating of plaster.

In the embodiment illustrated in Figs. 1 and2, the backing 1 is-a sheetof wirecloth which ma be of the kind used for flyscreens. pon thisbacking, strips 2, 2, of sheet iron, which may be galvanized orotherwise rust-proofed, or cut from tin or terne plate, are laidsubstantially parallel with each other transversely of the sheet fromedge to edge, these fiat strips being of a width suflicient to receivethe securing nails driven therethrough into the supporting studs orjoists 3, 3. The nailing strips or straps 2 are secured by spot weldingdirectly to the wire mesh and the securing nails 4 are driven throughthese straps and through the Wire mesh at 5 into the studs or joists 3.

The surface of the-board will be provided with marks 7 which may consistof indentations of any desired form to indicate the position ofthe-nailing strips, so that the nail may be driven through the center ofthe strip. 'Ihese strips will of course be of sufficientwidth to permita reasonable amount of variation in the driving of the securing nails.

As a means of securing the nailing strips 2 firmly in place in theplastic body of the boards, lugs 9 may be formed upon, or secured to thestrips 2, a preferred shape bein shown in Fig. 2, in which the upwar lybent member 9 is dovetailed to ofim the maximum resistance to withdrawalof the member from the composition 8.

The metallic reinforcement will be treated with a special heavy coatingof some rustproofing material before embedding it in the cement.

After the reinforcement is set in place, the plastic composition ispoured over and around the strips and backing, which may rest upon anysuitable support until the cement begins to set.

A secondary reinforcing fabric 11 is then placed upon the top. At theproper stage of setting of the plaster, pressure is applied to renderthe composition 8 denser and to force it into the backing 1 andreinforcement 11. The plastic composition passes through the meshes ofthe backing and of the secondary reinforcement so that the surface layeris a coating of plastic material, to which the ordinary finishing coatof plaster will firmly adhere for interior work, or to which stucco willcling to form a decorative surface for exterior work.

In assembling wall boards upon their supports it is customary to leave alittle space between their edges. It is not practicable to assembleboards to form an absolutely perfect joint, since the corner angles willvary from a true right angle and where the edges are struck or otherwisedamaged during shipment or handling, portions will be broken out and theedges will not meet to form a straight line. The expression in abuttingrelation, is therefore intended to define a relationship of two boardssuch that they lie with their edges in close proximity even though thejoint may be irregular and though the boards may not lie in actualcontact with each other.

One of the principal objections to the use of plaster boards has beenthe difficulty in securing a proper finish along the joints where theboards meet. Where such boards are made of paper pulp or other fibrousmaterial, there is almost always a certain amount of swelling andshrinking with atmospheric changes, and this action produces cracks sothat in some cases almost every joint can be discerned.

driven into the boards and cesses left by countersinking the nails. Intothis wet plaster, a reinforcing strip 12 of wire mesh is placed, thestrip being of sufficient width to overlap the nail heads on both of themeeting boards. Since the ordlnary studding is about two inches inthickness, the wire reinforcement 12 need not greatly exceed this width.The setting of the plaster holds the reinforcing strip in place withoutthe use of nails. The finishlng coat 13 completely conceals the flatridge made by the wire and plaster reinforcement along the joint andcracking is entirely prevented.

The strips 12 are preferably of wire, woven as a narrow band about twoor three inches in width. It will be supplied conveniently in rolls orbundles. By making a special narrow strip, the danger is avoided ofhaving projecting wire ends to interfere with the working of thefinishing coat.

If the strips are cut from a wide sheet, the edges will preferablybefolded back upon the surface of the strip.

"When a broad sheet of plaster board is supported at its edges and alongthe center line as shown in Fig. 1, sudden heavy pressure appliedbetween the studding on both sides of the intermediate stud may cause acrack due to the bending of the board over the central support.

To prevent this, a reinforcing strip 22, made of any of the fabricssuggested above in the desription of strips 12, is placed at rightangles to the mailing strips 2 along the center of the board eitherbefore or after the fabric reinforcement 11 is placed in position.

In practice the boards will be made thirtytwo inches wide and abouttwenty-seven inches high, the joints of all the boards being on as fewlines as possible so that the reinforcing strips 12 can be run along theedges of several boards at a time.

When nails are driven through a board 110 having other than a papersurface, the heads are ordinarily left exposed and the metallic nailtransmits the heat of flames to the wooden supporting beams causing arapid charring. The hot nails in the III charred wood cannot resist theoutward pull caused by the heavy material and the entire board pullsloose and falls, leaving a passage for the fire.

In the present system the nails are coun- 12 0 tersunk and aconsiderable thickness of plaster lies between the heads and the ex-.posed surface. The nails cannot be reached protecting layer intact overthe entire surface. The long projecting anchors on the nailing stripsengage firmly with the composition being interlocked with a largeportion of the mass and the nailing strips are welded to the 'wire mesh.When the nailing strip and reinforcing mesh are fastened to thesupports, the plastic material cannot fall off in sheets as in the caseof those forms of board in which the sole support of the composition isan inflammable aper surface.

Many variations and modifications can obviously be made in the structureherein illustrated, and I do not therefore wish to be limited to theexact details shown and described, but desire to claim my invention inany of its forms and modifications within the legitimate and valid scopeof the appended claims.

lVhat I claim is 1. A building structure comprising a plurality ofplastic composition panels ar ranged with their edges in abuttingrelation, a fabric reinforcing strip overlapping the abutting edges, anda surface coating of plastic material covering the panels and reinforcing strip.

2. A building structure comprising a plurality of plastic compositionpanels arranged with their edges in abutting relation, fastening meansadjacent to the edges of the panels, a reinforcing strip overlapping theabutting edges of the panels and overlying the exposed portions of thefastening means, and a surface coating of a plastic material tion of thepanels adjacent thereto.

3. A building structure comprising a wooden support, substantiallyfireproof composition boards having their meeting edges adjacent to eachother upon the support,

securing nails countersunk within the body ering therefor consisting ofa substantially fireproof composition having a metallic reinforcementembedded therein, securing means passing through the composition intothe support, and insulating means overlying the outer ends of thesecuring means toprovide a substantially fireproof surface.

5. A building structure comprising a support, two composition boardssecured to the support adjacent to their meeting edges, reinforcingnailing strips extending adjacent to the meeting edges within thecomposition body, securing means passing through the strips, areinforcing strip extending along the joint at the meeting edges andover the ends of the securing means, and a plastic composition coveringthe portion of the composition boards and the reinforcing strip adjacentto their meeting edges.

In testimony whereof I affix'my signature in presence of two witnesses.

CUR-RY ORA WALPER.

Witnesses:

Lnwrs E. FLANDERS, ARTHUR MINNIGK.

